Traditionally, manufacturers have used cross-sectional transmission electron microscopy to look for defects in devices, specifically around junctions inside a device where one metal diffuses with another. This involves a slicing and milling process – potentially causing more damage and exposing mechanisms to harmful oxidisation.

Now, for the first time, Professor Atsufumi Hirohata from York’s Department of Electronics has trialled an alternative non-destructive technique using a scanning electron microscope.

As most electronic devices can often contain over 40 layers of components, this new method allows precisely controlled electrons to scan a device and produce a microscopic image in nanometres.

This process is much faster than cross-sectional methods, taking only 10 minutes to one hour as opposed to three or four days. Since electron microscopes are also a standard tool in most labs, this method is considerably cheaper and more accessible.

Professor Hirohata said: “Our finding allows us to observe the inside conditions below the surface of a device, without requiring any slicing or milling that can cause damage. Being able to evaluate the inside conditions without breaking a device apart is very useful, as it allows us to image any intrinsic pinholes, voids and contamination hidden from the surface.

“This new technique provides a quicker, more cost-effective alternative to current cross-sectional methods, and could improve the production process for multiple industries such as electronics and medical manufacturers.”

Professor Hirohata and his team have applied for a patent on this imaging technique, and hope to roll the method out across manufacturers worldwide.

Further information:

Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam is published in Nature Communications.